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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Uniformidade e estabilidade da cor da madeira termorretificada de Tectona grandis L. f. / Uniformity and stability of color of the heat-treated Tectona grandis L. f. wood

LOPES, Juliana de Oliveira 26 April 2012 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-04-12T20:41:07Z No. of bitstreams: 1 2012 - Juliana de Oliveira Lopes.pdf: 1518311 bytes, checksum: 21fc297e17199bf911f4cf85812c2694 (MD5) / Made available in DSpace on 2017-04-12T20:41:07Z (GMT). No. of bitstreams: 1 2012 - Juliana de Oliveira Lopes.pdf: 1518311 bytes, checksum: 21fc297e17199bf911f4cf85812c2694 (MD5) Previous issue date: 2012-04-26 / CAPES / The teak wood (Tectona grandis L. f.) from young plantations (12 years old) has some undesirable characteristics in terms of color uniformity as well as presenting a high proportion of sapwood, which is distinguished from heartwood by the lower durability and light color. In addition, teak wood has color change when exposed to ultraviolet (UV) radiation, which depreciates the product over time. Heat treatments can be applied to change, standardize and stabilise the color of the wood, thus adding more value to the final product. In this context, the objectives of this study were: (1) to determine the effect of spacing between trees on the physical properties (density and moisture content) and the original color of wood, (2) to determine the color change of wood after heat treatments, (3) to evaluate the color uniformity of the wood (pieces containing heartwood and sapwood) after heat treatments and (4) to evaluate the color stability of heat-treated wood after UV radiation in accelerated aging conditions. Nine trees from three different levels of spacing (4 x 2 m, 5 x 2 m and 6 x 2 m) were used, with three trees per spacing. Samples of 150 x 75 x 20 mm were produced and divided into three groups: I: samples with a predominance of heartwood (? 75% heartwood in relation to sapwood), II: samples with 100% of sapwood and III: samples with approximately 50% heartwood and 50% sapwood. The groups I and II were used to determine the physical properties, wood color changes before and after heat treatments and color stability after exposure to UV radiation, whereas those of group III were used to determine the color uniformity after heat treatments. Heat treatments were performed in a laboratorial electric oven from Linn Elektro Therm under two temperatures: 180 and 200?C. Color measurements were performed using the portable spectrophotometer CM 2600d in the CIE-L*a*b* space. The accelerated aging test was performed in a QUV/Spray from Q-Lab chamber. The total cycle of exposure to UV radiation was 168 hours, and color measurements were taken to every 42 hours. The spacing affected the physical properties and the original color of wood. The heat treatment affected more the density of heartwood than sapwood. Heartwood and sapwood presented an average decrease of the 52% in equilibrium moisture content after heat treatments. Heartwood and sapwood had the same lightness pattern at the different spacings. After the heat treatment, wood had a loss of lightness, becoming darker, and this was more pronounced in the treatment at 200?C. Heartwood and sapwood presented different behavior for the coordinates a* and b* depending of spacing, before and after heat treatments. There was a greater formation of red hue and loss on yellow hue of heartwood and sapwood treated at 200?C. Heat treatments caused a higher color change on sapwood than heartwood, which provided greater uniformity to the pieces of wood with heartwood and sapwood. The color of sapwood heat-treated at 180oC woods had higher stability at UV radiation, thus demonstrating the potential of heat treatment to obtain products of higher added value. / A madeira de teca (Tectona grandis L. f.) proveniente de plantios jovens (12 anos de idade) apresenta algumas caracter?sticas indesej?veis em termos de uniformidade de cor al?m de apresentar alta propor??o de alburno, o qual distingue-se do cerne pela menor durabilidade e cor clara. Al?m disso, a madeira de teca apresenta altera??o de cor quando exposta ? radia??o ultravioleta (UV), o que acaba depreciando o material ao longo do tempo. Tratamentos termorretificadores podem ser aplicados para alterar, uniformizar e estabilizar a cor da madeira, agregando assim maior valor ao produto final. Neste contexto, os objetivos deste estudo foram: (1) determinar o efeito do espa?amento entre ?rvores nas propriedades f?sicas (densidade e teor de umidade) e na cor original da madeira, (2) determinar a altera??o da cor da madeira ap?s a termorretifica??o, (3) avaliar a uniformidade da cor da madeira (pe?as contendo cerne e alburno) ap?s os tratamentos termorretificadores e (4) avaliar a estabilidade da cor da madeira termorretificada ? radia??o UV em condi??es de envelhecimento acelerado. Foram utilizadas nove ?rvores de teca provenientes de tr?s espa?amentos (4 x 2 m, 5 x 2 m e 6 x 2 m), sendo 3 ?rvores para cada espa?amento. Amostras de 150 x 75 x 20 mm foram produzidas e divididas em tr?s grupos: I: amostras com predomin?ncia de madeira do cerne (? 75% de cerne em rela??o ao alburno), II: amostras com 100% de alburno e III: amostras com aproximadamente 50% de cerne e 50% de alburno. Os grupos I e II foram utilizados para determinar as propriedades f?sicas, a varia??o da cor da madeira antes e ap?s a termorretifica??o e a estabilidade da cor ap?s ? radia??o UV, enquanto que o grupo III foi utilizado para determinar a uniformidade da cor ap?s a termorretifica??o. A termorretifica??o foi realizada em um forno mufla el?trico laboratorial Linn Elektro Therm sob duas temperaturas: 180 e 200?C. As medi??es de cor foram realizadas atrav?s do espectrofot?metro port?til CM 2600d no espa?o CIE-L*a*b*. O ensaio de envelhecimento acelerado foi realizado em uma c?mara QUV/Spray da Q-Lab. O ciclo total de exposi??o ? radia??o UV foi de 168 horas, sendo realizadas medi??es de cor ? cada 42 horas. O espa?amento afetou as propriedades f?sicas e a cor original da madeira. A termorretifica??o afetou mais a densidade do cerne que do alburno. As madeiras de cerne e alburno apresentaram uma redu??o m?dia de 52% no teor de umidade de equil?brio ap?s a termorretifica??o. O cerne e o alburno apresentaram o mesmo padr?o de luminosidade nos diferentes espa?amentos. Ap?s a termorretifica??o, a madeira teve perda de luminosidade, tornado-se mais escura, sendo isso mais acentuado para o tratamento ? 200?C. As madeiras de cerne e alburno apresentaram comportamentos diferentes para as coordenadas a* e b* dependendo do espa?amento, antes e ap?s a termorretifica??o. Ocorreu uma maior forma??o de pigmento vermelho e perda de pigmento amarelo nas madeiras de cerne e alburno tratadas ? 200?C. A termorretifica??o proporcionou uma maior altera??o ? cor do alburno, o que resultou em uma maior uniformidade ?s pe?as de madeira contendo cerne e alburno. A cor da madeira de alburno termorretificada ? 180?C apresentou maior estabilidade ? radia??o UV, mostrando assim o potencial da termorretifica??o para obten??o de produtos de maior valor agregado.
52

Colour development in Pinus radiata D. Don. under kiln-drying conditions.

Dieste, Andrés January 2002 (has links)
This study quantifies discolouration on the surface of Pinus radiata boards during kiln drying, particularly kiln brown stain (KBS), and models it as a function of chemical compounds present in the wood closest to the surface. The discolouration was investigated with two experimental factors: drying time, which consisted in drying at 70/120 ℃ for 0, 8, 16 and 24 hours; and leaching, done at three levels, noleaching, mild and severe, to reduce the soluble compounds present in wood suspected of developing coloured compounds. The colour change was quantified using a reflectance photometer (colour system CIE Yxy, brightness) and by the analysis of digital photographs (colour system CIE Lab). The chemical analysis of the wood closest to the surface of the boards determined fructose, glucose, sucrose (HPLC), total sugar (sum of fructose, glucose and sucrose), total nitrogen (combustion gas analysis), and phenols discriminated by molecular weight (Folin-Ciocalteu method). In the cause-effect analysis, colour was the dependent variable, and drying time and the determinations of chemical compounds were independent variables. After statistical analysis (ANOVA and MANOVA) the dependent variables to be included in the models were luminance factor (Y), brightness (R457 and the blue-to-yellow scale of CIE Lab (b); and the independent variables were drying time, nitrogen, total sugar, and high-molecular-weight phenols. Linear (multivariate regression) and non-linear models (Neural Networks) showed that discolouration during kiln drying was best predicted when the luminance factor (Y) was used to quantify colour change as a function of the content of nitrogen-containing compounds and drying time. Furthermore, the data were fitted into an empirical model based on simple reaction kinetics that considered the rate of discolouration as a function of nitrogen concentration. The results suggest that nitrogen could act as a limiting reactant in Maillard-type reactions that produce colour during kiln drying.
53

AVALIAÇÃO DAS PROPRIEDADES ÓPTICAS DE UMA CERÂMICA E DE UM COMPÓSITO, COM E SEM POLIMENTO, SUBMETIDOS A MEIOS E TEMPOS DE IMERSÃO DISTINTOS. / EVALUATION OF OPTICAL PROPERTIES OF A CERAMIC AND A COMPOSITE WITH AND WITHOUT POLISHING SUBMITTED TO DIFFERENTE MEDIA AND IMMERSION TIMES

Dellazzana, Fernando Zurlo 20 August 2013 (has links)
The aim of this study was to verify the color and opacity of a ceramic system (IPS e.max Ceram - Ivoclar Vivadent) and an indirect composite resin (SR Adoro Ivoclar Vivadent), with and without polishing, when stored in different media (immersed in water and red wine. Thirty-six test specimens (sp) 12mm in diameter and 2mm thick were built for each material. Immediately after ceramic sintering, and polishing of the composite, half the sp of each material were polished with a polishing system (OptraFine P Disc - Ivoclar Vivadent), washed in water and dried with gauze. The other half of the sp remained unpolished. Initial color and Percentage of Opacity were measured with a spectrophotometer (SP60 - X-Rite), using the CIE L* a* b* system. The sp of each material were divided into groups (n=9) according to the storage media (water and red wine). Color readings were performed at the time intervals of 7 and 30 days. Color alteration (ΔE) and percentage of opacity were calculated for each time interval and the data were submitted to statistical analysis (5%). When the composite, irrespective of polishing, was immersed in water, its �E increased after 30 days storage in water, whereas for IPS e.max, changes were observed only with polishing. However, after 7 days of immersion in red wine, SR Adoro with polishing presented changes, which seemed to continue increasing after 30 days, and also without polishing. IPS e.max presented greater color changes in 30 days with and without polishing in comparison with 7 days. IPS e.max showed greater opacity than SR Adoro. In SR Adoro there is variation in opacity over the course of immersion time in wine, whereas in IPS e.max, there was no change in opacity. / O objetivo deste trabalho foi verificar a cor e a opacidade de um sistema cerâmico (IPS e.max Ceram - Ivoclar Vivadent) e de um compósito de confecção indireta (SR Adoro Ivoclar Vivadent), com e sem polimento, quando armazenados em meios diferentes e por tempos distintos. Foram confeccionados 36 corpos de prova (cps) para cada material com 12 mm de diâmetro e 2 mm de espessura. Imediatamente após a sinterização da cerâmica e polimerização do compósito, a metade dos cps de cada material foi polida com um sistema de polimento (OptraFine P Disc - Ivoclar Vivadent), lavada em água e seca com gaze. A outra metade dos cps permaneceu sem polimento. Foi realizada a mensuração inicial de cor e o Percentual de Opacidade com um espectrofotômetro (SP60 - X-Rite), utilizando o sistema CIE L* a* b*. Os cps de cada material foram divididos em grupos (n=9) de acordo com os meios de armazenamento (água e vinho tinto). Leituras foram realizadas nos períodos de 7 e 30 dias. A alteração de cor (ΔE) e o Percentual de Opacidade foram calculados para cada período e os dados foram submetidos à análise estatística (5%). O compósito, independente do polimento, quando imerso em água após 30 dias de armazenamento aumentou o seu �E, enquanto que no sistema cerâmico a alteração foi observada apenas no grupo com polimento. Já em 7 dias de imersão em vinho o SR Adoro com polimento apresentou alteração, o que parece permanecer aumentando após 30 dias e também sem polimento. O IPS e.max apresentou maior alteração de cor em 30 dias com e sem polimento comparado com 7 dias. O IPS e.max demonstrou maior opacidade que o SR Adoro.
54

TRANSLUCIDEZ E VALOR: ANÁLISE DO COMPORTAMENTO DAS PROPRIEDADES ÓPTICAS EM RESINAS COMPOSTAS ESTÉTICAS / TRANSLUCENCY AND VALUE: OPTICAL PROPERTIES BEHAVIOR IN AESTHETIC RESIN COMPOSITES

Santos, Iuri Silveira dos 11 June 2015 (has links)
This study aimed to evaluate the translucency and value with different combinations of enamel , dentin and body of each composite regarding a standard thickness (1,5mm). Three different resin composites commercially available with a standard shade (A1), IPS Empress Direct, Charisma Diamond and Filtek Z350 XT were evaluated. A stainless steel matrix was used to prepare ninety disc-shaped specimens with 11mm diameter and 1,5mm thickness. The specimens were randomly allocated in 18 groups (n=5) according to different combinations of enamel , dentin and body presented in each resin composite evaluated. After light curing, specimens were stored in deionized water at 37º C for 24h. Three consecutive readings were performed according to the CIE L*a*b* color scale relative to the standard illuminant D65 on reflection spectrophotometer (SP60 - EX-Rite). The optical properties of translucency and value were measured by the parameters translucency (TP) and lightness in white background (L*w) and black background (L*b), respectively. The mean TP, L*w and L*b were analyzed by ANOVA (General Linear Models) and Tukey s post hoc tests (α =0.05). Scatter plots together with Spearman´s correlation coefficient were used to assess the relationship between TP and L*w and TP and L*b values. The groups had statistical significant different values (p=0.000). The resin composite Empress Direct when only a layer of enamel were employed presented the highest TP value, whereas the resin composite Filtek Z350 XT with a single layer of dentin presented the lowest TP value. A negative and strong correlation between TP and L*b and a positive and weak correlation between TP and L*w were observed. Optical properties as translucency and value rely on the material used. In general, there was statistical difference between the groups for TP and L* / Este estudo tem como objetivo analisar o comportamento óptico de diferentes resinas compostas, em distintas combinações de esmalte, dentina e corpo de cada composto em relação à espessura padrão (1,5mm) na percepção da translucidez e valor. Foram analisadas três marcas comerciais de resina composta (IPS Empress Direct, Charisma Diamond, Filtek Z350 XT) na cor A1. Uma matriz metálica foi utilizada para confeccionar noventa espécimes (1,5mm de espessura e 11mm de diâmetro). Os espécimes foram randomizados e divididos em 18 grupos (n=5) conforme as possibilidades de combinações de esmalte, dentina e corpo. Após a fotopolimerização, os espécimes foram armazenados em água deionizada por 24h a 37°C. Três leituras consecutivas foram realizadas por um espectrofotômetro de reflexão (SP 60 EX-Rite) relativo ao iluminante padrão D65 de acordo com o sistema CIE L* a* b*. As propriedades ópticas, translucidez e valor, foram mensuradas pelo parâmetro de translucidez (TP) e pela variável L* sobre fundo preto e branco respectivamente. A média dos valores do TP, L*b e L*p foram analisadas por ANOVA (Modelo Linear Geral) e testes Tukey s post hoc (α=0,05). Gráficos de dispersão juntamente com o coeficiente de correlação de Spearman entre TP e L*p e TP e L*b foram calculados. Os grupos apresentaram diferença estatística (p = 0,000). A resina composta Empress Direct somente de esmalte apresentou o maior valor de TP, enquanto Filtek Z350 XT com uma única camada de dentina apresentou o menor valor de TP. Há uma forte correlação negativa entre TP e L*p e uma fraca correlação positiva entre TP e L*b. Propriedades ópticas de translucidez e valor são dependentes do material utilizado. De maneira geral, houve diferenças entre os grupos estudados quando analisados o TP e L*.
55

SYSTEM GENETIC ANALYSIS OF MECHANISMS UNDERLYING EXCESSIVE ALCOHOL CONSUMPTION

Smith, Maren L. 01 January 2016 (has links)
Increased alcohol consumption over time is one of the characteristic symptoms of Alcohol Use Disorder (AUD). The molecular mechanisms underlying this escalation in intake is still the subject of study. However, the mesocortical and mesolimbic dopamine pathways, and the extended amygdala, because of their involvement in reward and reinforcement are believed to play key roles in these behavioral changes. Multiple gene expression studies have shown that alcohol affects the expression of thousands of genes in the brain. The studies discussed in this document use the systems biology technique of co-expression network analysis to attempt to find patterns within genome-wide expression data from two animal models of chronic, high-dose ethanol exposure. These analyses have identified time-dependent and brain-regions specific patterns of expression in C57Bl/6J mice after multiple exposures to intoxicating doses of ethanol and withdrawal. Specifically, they have identified the PFC and HPC as showing long-term ethanol regulation, and identified Let-7 family miRNAs as potential gene expression regulators of chronic ethanol response. Network analysis also indicates neurotransmitter release and neuroimmune response are very correlated to ethanol intake in chronically exposed mice. Examining gene expression response to chronic ethanol exposure across a variable genetic background revealed that, although gene expression response may show conserved patterns, underlying differences in gene expression influence by genetic background may be what truly underlies voluntary ethanol consumption. Finally, combined network analysis of gene expression in the prefrontal cortex (PFC) of mice and macaques following prolonged ethanol exposure demonstrated that neurotransmission, myelination, transcription, cellular respiration, and, possibly, neurovasculature are affected by chronic ethanol across species. Taken together, these studies generate several new hypothesis and areas of future research into the continued study of druggable targets for AUD.
56

Utiliza??o do laser de diodo como alternativa no tratamento de superf?cie em restaura??es CAD/CAM

Bettinelli, Juliana Doncatto 10 January 2017 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-05-25T14:55:38Z No. of bitstreams: 1 TES_JULIANA_DONCATTO_BETTINELLI_COMPLETO.pdf: 2435463 bytes, checksum: 80f6606ba1ecc5861b22ef0b6b9e87de (MD5) / Made available in DSpace on 2017-05-25T14:55:38Z (GMT). No. of bitstreams: 1 TES_JULIANA_DONCATTO_BETTINELLI_COMPLETO.pdf: 2435463 bytes, checksum: 80f6606ba1ecc5861b22ef0b6b9e87de (MD5) Previous issue date: 2017-01-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Since the 1970s, the application of the CAD / CAM technique has been suggested in the dental clinic with the aim of simplifying, automating and guaranteeing quality levels with micrometric adaptations of our dental prostheses4,5. The objective of this study was to evaluate the viability of the diode laser as an alternative to hydrofluoric acid and aluminum oxide blasting compared to the machining process in the surface treatment of the following restorative materials: hybrid ceramics, nanoceramic resin, reinforced lithium silicate ceramics by zirconia, feldspathic ceramics, vitreous ceramics with crystalline structure of lithium disilicate, vitreous ceramics with crystalline structure of leucite. A specimen was prepared for each of the seven CAD / CAM restorative materials; And, this was divided into four parts. The dimensions of the specimens were 1cm in length and 1cm in width, in the thickness of 1mm, color A2. The surface area of the specimen was subdivided into quadrants; (A) was applied to the diode laser, (B) received the blasting of aluminum oxide, (C) received the application of hydrofluoric acid (5 or 10%) or cleaning with isopropyl alcohol (10%); As indicated by the manufacturer, (D) no conditioning was applied and the surface passed through the machining process only. Images were taken at a 15,000- fold increase (SEM). For the surface roughness test, ten measurements were taken, with cut-off 0.25. Statistical data were submitted to ANOVA and Tukey's test. Knowing the need to seek new alternatives of a conditioning protocol on the surface of restorative materials in CAD / CAM, it was highly effective, fast, simplified and mainly safe. It can be stated that the use of the diode laser seems to be feasible for the surface treatment of ceramic with crystalline structure of lecithin Empress CAD and ceramic feldspathic Cerec Blocs CAD / CAM, as it produced changes in the surface of these ceramics studied. / Desde a d?cada de setenta, a aplica??o da t?cnica CAD/CAM vem sendo sugerida na cl?nica odontol?gica com o objetivo de simplificar, automatizar e garantir n?veis de qualidade com adapta??es microm?tricas das nossas pr?teses dent?rias4,5. O objetivo deste estudo foi avaliar a viabilidade do laser de diodo, como alternativa ao ?cido fluor?drico e jateamento com ?xido de alum?nio em compara??o ao processo de usinagem no tratamento superficial dos seguintes materiais restauradores: cer?mica h?brida, resina nanocer?mica, cer?mica de silicato de l?tio refor?ada por zirc?nia, cer?mica feldsp?tica, cer?mica v?trea com estrutura cristalina de dissilicato de l?tio, cer?mica v?trea com estrutura cristalina de leucita. Foi confeccionado um corpo de prova para cada um dos sete materiais restauradores em CAD/CAM; e, este foi dividido em quatro partes. As dimens?es dos corpos de prova foram de 1 cm de comprimento por 1cm de largura, na espessura de 1mm, cor A2. A ?rea de superf?cie do corpo-de-prova foi subdivida em quadrantes; de forma que em (A) foi aplicado o laser de diodo, (B) recebeu o jateamento de ?xido de alum?nio, (C) recebeu a aplica??o de ?cido fluor?drico (5 ou 10%) ou limpeza com ?lcool isoprop?lico (10%); conforme indica??o do fabricante, (D) n?o foi aplicado condicionamento e a superf?cie passou apenas pelo processo de usinagem. Foram realizadas imagens no aumento de 15.000 vezes (MEV). Para o teste de rugosidade superficial, foram tomadas dez medidas, com cut-off (valor de corte) 0,25. Os dados estat?sticos obtidos foram submetidos ? ANOVA e ao teste de Tukey. Sabendo-se da necessidade de buscar novas alternativas de um protocolo de condicionamento na superf?cie dos materiais restauradores em CAD/CAM, que fosse altamente eficaz, r?pido, simplificado e principalmente seguro. Pode-se afirmar que a utiliza??o do laser de diodo parece ser vi?vel para o tratamento superficial da cer?mica v?trea com estrutura cristalina de leucita Empress CAD e cer?mica feldsp?tica Cerec Blocs CAD/CAM, pois produziu altera??es na superf?cie destas cer?micas estudadas.
57

Modelagem de nicho, variabilidade gen?tica e conserva??o de Anomochloa maranteidea Brongn (Poaceae) end?mica do sul da Bahia, Brasil

Vieira, Jo?o Paulo Silva 29 September 2017 (has links)
Submitted by Jadson Francisco de Jesus SILVA (jadson@uefs.br) on 2018-02-21T21:35:29Z No. of bitstreams: 1 Disserta??o Pos banca Final.pdf: 10846078 bytes, checksum: 3a74cdd39783b17cdb4b6e3cc625186c (MD5) / Made available in DSpace on 2018-02-21T21:35:29Z (GMT). No. of bitstreams: 1 Disserta??o Pos banca Final.pdf: 10846078 bytes, checksum: 3a74cdd39783b17cdb4b6e3cc625186c (MD5) Previous issue date: 2017-09-29 / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / The genus Anomochloa Brongn. includes a single species, A. marantoidea Brongn., known as the earliest extant grass. It is a rare species from the Brazilian Atlantic rainforest, endemic to the southern Bahia. Only two populations were discovered so far, occurring out protected areas with few individuals registered, thus, A. marantoidea is considered critically threatened with extinction. The study of this species is highly important to understand evolutionary processes within Poaceae family. The present study aimed to increase the knowledge about its geographic range, to evaluate its potential areas of occurrence and to access its genetic diversity, detecting probable genetic threats as a result of its small population size. These data are essential for the development of conservation programs. Two new populations were recently discovered and the modeled ecological niche to A. marantoidea did not diverge from the expected geographical extent, denoting high climatic restriction and reasserting its rarity. The variables Index of Tree Cover and Rainfall are the main components that influence its restricted distribution. The levels of genetic diversity within the populations accessed by molecular markers indicate that A. marantoidea exhibits capacity for favorable response in short time and a conservation plan may be efficient to maintain its current genetic diversity. This diversity is correlated to the population size, for this reason, the propagules necessary for establishing new populations in climatically suitable sites must be originated from the largest populations. Genetic structure analysis suggests recent fragmentation and low gene flow among populations showing high levels of inbreeding. In this way, we recommend human mediated gene flow between the populations in order to mitigate the risks of inbreeding depression. It is hypothesized that the genetic differences among populations are caused mostly by random drift, resulting in populations with few individuals more genetically differentiated than the large ones. This implies that a minimum number of individuals (~100) is desirable to avoid the decrease of genetic diversity in populations. / O g?nero Anomochloa Brongn. inclui uma ?nica esp?cie, A. marantoidea Brongn., reconhecidamente a mais antiga entre as gram?neas viventes. ? uma esp?cie rara, end?mica da Mata Atl?ntica do sul do estado da Bahia com apenas duas popula??es conhecidas at? pouco tempo, ambas com poucos indiv?duos e nenhuma em ?rea protegida, sendo considerada criticamente amea?ada de extin??o. O conhecimento sobre essa esp?cie ? de suma import?ncia para compreender a evolu??o dentro da fam?lia, e assim, o presente trabalho visou ampliar o conhecimento acerca da extens?o da distribui??o geogr?fica da mesma e avaliar suas ?reas potenciais de ocorr?ncia, bem como conhecer os n?veis de diversidade e amea?as gen?ticas resultantes do pequeno tamanho populacional, dados essenciais para programas que visem sua conserva??o. Duas novas popula??es foram localizadas recentemente e o nicho ecol?gico modelado n?o divergiu da distribui??o esperada, indicando uma alta restri??o clim?tica e reafirmando a raridade da esp?cie. O ?ndice de cobertura vegetal e a precipita??o foram os principais requisitos ambientais a influenciar sua distribui??o t?o restrita. Os n?veis de diversidade gen?tica nas popula??es inferidos por marcadores moleculares indicam que a esp?cie tem capacidade para responder imediatamente bem em curto prazo e que um plano de conserva??o pode ser eficiente em manter a atual diversidade espec?fica. Esta diversidade se mostrou relacionada com tamanho populacional, assim, prop?gulos para o estabelecimento de novas popula??es em s?tios climaticamente adequados devem ser obtidos das maiores popula??es. An?lises de estrutura??o gen?tica sugerem fragmenta??o recente e indicam baixo fluxo g?nico entre as popula??es conhecidas da esp?cie, com consequentes altos n?veis de endogamia, por isso ? recomendado fluxo g?nico mediado por atividade humana entre as popula??es para evitar depress?o endog?mica. ? hipotetizado que diferen?as gen?ticas entre as popula??es s?o causadas majoritariamente por deriva aleat?ria, o que tornou popula??es com menos indiv?duos mais diferenciadas geneticamente daquela com o maior n?mero. Isso implica que um n?mero m?nimo de indiv?duos (~100) ? desej?vel para evitar redu??o na diversidade gen?tica das popula??es.
58

Desenhos de couro: registro e mem?ria dos desenhos no encouramento do vaqueiro sertanejo

Neiva, Suria Seixas 17 February 2017 (has links)
Submitted by Jadson Francisco de Jesus SILVA (jadson@uefs.br) on 2018-02-21T22:38:38Z No. of bitstreams: 1 NEIVASuriaSeixas_ DESENHOS_DE_COURO.pdf: 272955981 bytes, checksum: b4858840e27db87b17f281c3e9fda9f2 (MD5) / Made available in DSpace on 2018-02-21T22:38:38Z (GMT). No. of bitstreams: 1 NEIVASuriaSeixas_ DESENHOS_DE_COURO.pdf: 272955981 bytes, checksum: b4858840e27db87b17f281c3e9fda9f2 (MD5) Previous issue date: 2017-02-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This dissertation presents the designs made from leather used by the brazilian northeast?s country cowboys: a type of surface design which can become a working gear but also a fashionable apparel. This tooled and carved leather has been made by generations in the sert?o and it is named here after ?desenho de couro?. The purpose of this work is to approach the manifestations of such ornamental leather technics considering their regional and historical presented aspects, or preexistences of its present form. The aesthetic and technical connections among the different expressions of the leather designs are understood through the survival dialetics of the images in the collective memory. This comes to be the art history methodology proposed by Warburg. Considering that is still possible to contact living masters of leather in activity, and to collect information regarding the technique transmission, this resource was used in order to understand the aesthetics and uses of that leather culture, which has its ancestral in the iberic-mudeyyan leatherwork. Both the documents of leather trade in the century XVIII, as well as of the history of the livestock in the Brazilian countryside corroborates with the hypotheses regarding the influence of the Iberian leather culture and its productive main points, today, in the Bahia countryside around Feira de Santana and Ipir?, as in Cariri from Pernambuco. The study of this leather design, more than a record of a Brazilian visual production, it is an living document of the national leather traditions and an outstanding element in the construction of the cowboy's identity as well as of an economic production and material culture of Brazil. / Esta disserta??o apresenta o desenho do encouramento dos vaqueiros sertanejos do nordeste: um desenho de superf?cie, de natureza indument?ria, ora laboral, ora social, que ? produzido h? gera??es nos sert?es, denominado aqui como desenho de couro. O objetivo deste trabalho ? abordar as manifesta??es desse desenho ornamental em superf?cie de couro por seus aspectos regionais, presentes, e hist?ricos, ou preexistentes. As conex?es est?ticas e t?cnicas, entre as diferentes express?es dos desenhos de couro, consideraram a dial?tica da sobreviv?ncia das imagens na mem?ria coletiva ? isto ?, a metodologia de hist?ria da arte proposta por Warburg. Foi lan?ado m?o do recurso, ainda poss?vel, de contatar mestres do couro em atividade e coletar informa??es a respeito da transmiss?o das t?cnicas, est?ticas e usos dessa cultura coureira, que tem seus ancestrais na corioplastia ?bero-mudej?r. O respaldo documental de tr?nsitos comerciais de couro no s?culo XVIII bem como da hist?ria da pecu?ria no sert?o brasileiro, corrobora com as hip?teses aventadas a respeito da influ?ncia da corioplastia ib?rica e da sua concentra??o produtiva, hoje, no sert?o baiano dos arredores de Feira de Santana e Ipir?, como no Cariri pernambucano. O estudo do desenho de couro, para al?m do registro de uma produ??o visual brasileira, ? um documento vivo da corioplastia nacional e um elemento marcante na constru??o n?o apenas da identidade do vaqueiro como da produ??o da economia e da cultura material do Brasil.
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A??o do plasma rico em plaquetas e seus fatores de crescimento na cirurgia dos microimplantes capilares

Uebel, Carlos Oscar 29 December 2006 (has links)
Made available in DSpace on 2015-04-14T13:35:25Z (GMT). No. of bitstreams: 1 385561.pdf: 1030216 bytes, checksum: e224065ca6fb4a1d5a9468a932755962 (MD5) Previous issue date: 2006-12-29 / Introdu??o e Objetivos: A cirurgia com a utiliza??o dos microimplantes capilares (MICs) tem sido adotada amplamente no tratamento da calv?cie masculina e feminina. A integra??o destes microenxertos pode variar entre 70% a 85% e, embora todos os cuidados sejam tomados desde sua obten??o na ?rea doadora at? sua prepara??o e implanta??o na ?rea calva, ? necess?rio levar em conta a apoptose e a necrose como fatores que interferem neste processo. Considerando esta perda como relevante na cirurgia da calv?cie, estabeleceu-se um trabalho experimental utilizando o plasma rico em plaquetas (PRP) e seus fatores de crescimento, obtido do pr?prio sangue do paciente, no intuito de estimular a integra??o e o crescimento dos MICs. A exemplo de outros trabalhos publicados com PRP e seus fatores plaquet?rios, sobretudo nas ?reas da traumatologia, odontologia, maxilofacial e na cirurgia pl?stica, acreditou-se neste protocolo cir?rgico como uma nova contribui??o para a cirurgia da calv?cie com a utiliza??o dos MICs. Material e M?todos: Foram selecionados 23 pacientes masculinos portadores de calv?cie do tipo padr?o, na faixa et?ria de 22 a 55 anos, para um trabalho experimental de controle interno, emparelhado, em que cada paciente serviu como seu pr?prio controle. Delinearam-se duas ?reas calvas de 2,5 cm x 2,5 cm em que, ? direita do paciente, se implantaram os MICs embebidos em PRP com seus fatores de crescimento e, ? esquerda, os MICS considerados controles. Ao final de 7 meses de p?s-operat?rio realizou-se a contagem definitiva dos microimplantes desenvolvidos. Os dados quantitativos foram descritos com m?dia e desvio padr?o. A compara??o do lado controle com o lado experimental foi realizada por teste t de Student para amostras emparelhadas. Foi tamb?m estimado o efeito do m?todo experimental sobre o controle atrav?s da diferen?a m?dia entre o n?mero de MICs dos dois lados seguido de seu intervalo de confian?a de 95%. Os dados foram processados e analisados com o aux?lio do programa SPSS vers?o 12.0. Resultados: Na compara??o da contagem de MICs entre o lado experimental tratado com PRP e seus FCs e o lado controle, foi observada uma diferen?a estatisticamente significativa (P < 0,001). O lado esquerdo, considerado controle, teve um crescimento m?dio de 16,7 MICs/cm2 enquanto o lado direito, onde se utilizou o PRP, teve um crescimento de 18,9 MICs/cm2. Isto representou uma diferen?a de 13,6% a maior na densidade capilar. Alguns pacientes tiveram diferen?as menores do que 5% e outros foram considerados casos excepcionais, com 31% e 52% de aumento na densidade capilar. Esta variabilidade deve ser considerada com cautela e novos estudos dever?o ser estabelecidos observando-se tamb?m idade, fumo, exerc?cios f?sicos e dieta alimentar. Conclus?o: De acordo com os resultados obtidos, houve um rendimento consider?vel superior de 13,6% no lado direito onde se utilizaram os MICs embebidos no PRP e seus FCPs. Houve efic?cia e integra??o melhores, resultando num maior n?mero de fol?culos e numa maior densidade capilar, o que trouxe um resultado positivo na cirurgia da calv?cie masculina do tipo padr?o com o uso do PRP e seus FCPs.
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Improving the stability of the black carrot (Daucus carota L.) colourant

Iliopoulou, Ioanna January 2016 (has links)
The replacement of artificial with natural dyes is one of the most challenging research fields in the food production area. Recent studies have shown that some frequently used synthetic colours, called the “Southampton 6 Colours” may be linked with hyperactivity in children. The purpose of this work is to analyse the degradation behaviour of black carrot, a natural, red dye commonly used for colouring food products, and subsequently improve its stability during heat and storage conditions. The stability of the black carrot mixture to heat exposure was investigated at a range of pH values by heat-treating aqueous solutions in a domestic oven at around 180oC to maintain the temperature at 100oC and the powdered material in a furnace at 180oC (typical baking conditions). 1H NMR (800 MHz) spectroscopy was used for the assignment of the aromatic chemical shifts of the black carrot mixture by overlaying them with the characterised 1H NMR chemical shifts of the individual components separated by RP-HPLC. Integration of high-resolution 1H NMR (800 MHz) spectra was used to follow the relative degradation of each of the components. Different procedures for the complexation of black carrot with metal oxides were developed, for which colourants of different colour shades were prepared. Spectroscopic techniques were used to follow the degradation of the complexes which were heat-treated at 180oC. Nano-scale investigation of the metal oxide powders was also carried out. The optimised colourants were tested on a bench scale and subsequently on an industrial scale in food pilot procedures. The successful complexes produced were found to be more heat stable compared to the commercial black carrot dye. The developed technologies are cheap and easy-to-produce methods to create intense heat and storage stable coloured pigments which can be used for the replacement of existing artificial dyes during food processing.

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